Messy Mid Week Possible Following Season's First Significant Winter Storm This Weekend
Tropics & Polar Domain in Conflict
The first weekend of the year promises to be a crucial point of inflection for the the 2023-2024 winter season. Not only will this weekend's impending winter storm have a significant impact on Sunday travel plans, but concurrent with this will be developments in the polar stratosphere that will have important implications on the balance of the winter season. Incidentally, there is now strong agreement amongst guidance that the long awaited split of the polar vortex that has been eagerly anticipated dating back to this past fall (between Christmas and January 8th) will be taking place concurrent with our Sunday snowfall.
Despite the fact that a technical SSW may not occur.
This is reflected by what is forecasted to be a very disturbed polar domain for the foreseeable future.
However, the deep trough that is forecasted to amplify over the Western CONUS this weekend is also forecasted to persist well into the month of January.
This is due to the fact that the MJO is forecasted to amplify in phase 4 by mid month.
This will only serve to bolster the west coast trough per both the MJO phase 4 January composite:
And MJO regression guidance.
The synoptic evolution that will follow includes the polar vortex lobe in the vicinity of James Bay initially descending into the western US.
A sequence that will reenforce the deep western trough at the same time that a major storm system is ejecting out of the Southwest next week.
While primarily rainfall is expected across the region, stay tuned for potential updates over the course of the next week for updates regarding how this system will interact with the developing NAO block.
INITIAL THREAT ASSESSMENT: